What pulley can I run without a chip?

[jeffsavage]

I don't know if I'm going to do it or not. But have had the Cobra since last Spring... did Magnaflow exhaust, K&N FIPK, Tri-ax shifter so far. I have been hesitant about getting into the realm of non-warrenty friendly mods like chip and pulley... due to cost of engine. But I modded the hell out of my 02 Lightning when I had it with no issues, and from what I have read in the last year on this forum peoples' cars are holding up well from some pretty radical work.
So, I want to start off small for now. What upper pulley can I get that I can stick on, get a couple more PSI of boost, and not have to install a chip, different plugs, etc. Lightning owners can get by doing this with a 2lb lower... what is the equivilant for a Cobra? And is this advised... will I have any troubles? And can stock pulley go back on easy enough in case of warrenty issues?
Thanks for any advise!

 

[B03Cobra]

None, heck I would even strap a stock Cobra on a dyno to get a/f a few from the factory have had crazy a/f numbers. Be safe, or dont do it, but its your baby... I think they say the 3.1 or 3.2 can be used with mixed results.

 

[ALA G8R]

A 3.4 can be used to add 2lbs additional boost without concern. I have been there and done that. There has been a bunch of discussion on this topic. Search and ye shall find.

 

[RickSvt]

I am using a 3.2, no problems. Like they all say though, just listen to it and if you can, take it to the dyno....I havent yet, but I also havent heard any funny noises.

Rick

 

[CobraBob]

Like AlaG8R said, a 3.4 does not need a chip or tune. And quite a new folks have done same with the 3.2 as well. Best to hit the dyno and check your A/F and timing. You want to be sure you're not getting any detonation. Personally I would at least do a Predator tune. You'll pick up more power and a lot more torque, too.

 

[caveman6666]

Originally posted by B03Cobra
None, heck I would even strap a stock Cobra on a dyno to get a/f a few from the factory have had crazy a/f numbers. Be safe, or dont do it, but its your baby... I think they say the 3.1 or 3.2 can be used with mixed results.

Agree. Penny wise, pound foolish, and all that noise. I wouldn't even consider it.

 

[CobraBob]

Just curious. Those who have chips or the Predator, do you re-tune your car every time you change the upper or lower pulley?

 

[Chonger]

If you are going to do a pulley without a tune I would not equate any specific pulley size as being safe. I would say go as small as you can depending on a safe AF. Just remember every car is different. Doing a mod on one car (especially a pulley) may get you a different AF ratio on another. I have seen this first hand. Two cars with the exact same mods had a very different AF chart.

 

[flyn high again]

One of the Chicago guys has been running a 3.0 without a tune since last year [I assume he still has it although I haven't seen him for a couple months]. I don't know if I would recommend that, though. As stated above, A/F readings on a dyno will let you know if you are OK with a smaller pulley than stock. A dyno run is cheap insurance when you think about what a new engine costs.